1. Field of the Invention
The disclosure relates to a switching power supply circuit and, more particularly, to a switching power supply circuit with an overshooting protecting function.
2. Description of the Related Art
A switching power supply is a common power supply circuits, and it is usually used in a microprocessing system and a computer system. The switching power supply adjusts an input voltage to a required output voltage.
However, a load may change along with time or different situations in practical operation. For example, when a load device (such as a microprocessor) executes a specific task (such as an operation task) may need a higher driving power, that is to say, the load increases; after the specific task is finished, the load may sharply decrease.
When the load of a load device rapidly decreases, a resistance of the load is rapidly changed, an instantaneous voltage of an output voltage may exceed a maximum allowable voltage of the circuit, which is the transient overshooting and may cause the power supply circuit unstable.